The lack of the existence of low cost, effective tuning technology is problematic in the industry of microwave components and antennas to name a few. Tuning may be defined as the ability to change a dielectric constant and translates in the microwave component field as being able to use the same component and change the frequency of operation by just changing the input voltage. It may allow for a single filter to frequency hop during operation. For the antenna world, being able to tune using low cost technology would create a new class of antennas referred to as phased array antennas that could be used in the common household instead of being limited to large government systems. Phased array antennas may be described as electronically scanning antennas. It is understood that although the present background may describe the shortcomings of one use of tunable material, to wit, phased array antennas, it is appreciated that the present invention is not limited to antennas.
Presently, there are methods to tune and build phased array antennas. One problem with existing methods is that they are not low cost and/or they are cumbersome and therefore limit the usage. Thus, what is needed is a new class of materials for these types of phased array antennas that would facilitate the antennas being more compact, lighter, have less expensive hardware costs, and be less expensive to operate
Existing technologies for scanning that have been tried for practical phase shifter applications are ferrite phase shifters and semiconductor-diode phase shifters. Although ferrites are currently the most widely used type of phase shifter materials, they are mostly limited to military applications. The major reason for this is that they are very expensive to manufacture. Also, they are not designed to work in a broadband situation. When the frequency changes, a whole new set of materials has to be designed and manufactured. Further, they are also very bulky in size and heavy and these phase shifters can not be made in a planar fashion. Ferrites are also driven by high power due to the fact that they activate based on current.
Diode phase shifters are high cost because they require active electronic circuits to be added to the design in order to compensate for their high loss at microwave frequencies and do not have good power handling characteristics. When power is put through the diode they start to behave in a very non-linear fashion or they breakdown. Diodes also require holding power in order to maintain accuracy as well as power during switching.
Thus, what is needed is a low loss but still tunable composite material with reasonable dielectric constants and a method of producing such material and applications utilizing this material.